Tractor mounted earth working tool



y 25, 1954 M. WOOLDRIDGE 2,679,120

TRACTOR MOUNTED EARTH WORKING TOOL Filed Nov. 20, 1948 3 Sheets-Sheet 1 mvem'orz Mack Woo/drlbye M IL npQ/f ATTORN EY M. WOOLDRIDGE TRACTOR MOUNTED EARTH WORKING TOOL May 25, 1954 3 Sheets-Sheet 2 Filed NOV- 20, 1948 INVENTOQ.

/ 5 ATTO QM EV y 25, 1954 M. WOOLDRIDGE 2,679,120

TRACTOR MOUNTED EARTH WORKING TOOL Filed Nov. 20, 1948 3 Sheets-Sheet 3 F'IIEI' IEI JNVENTOQ. Mack Woa/drlb ge Patented May 25, 1954 TRACTOR MOUNTED EARTH WORKING TOOL Wooldridge, Oakland, Calif. Application November 20, was, Serial No. 61,260

1 Claim.

1 This invention relates to a new and improved earth working tool and particularly to one which is particularly suited for use with a tractor of the track laying type.

As is well known 1n the art, a track laying type tractor includes a main frame having two side frames hingedly mounted on opposite sides and at one end or the mainframe, the latter being supported by a spring which extends between the side frames to provide support for the forward portion of the main frame. Th term main frame is somewhat general, for it includes the engine, clutch and transmission structure, these usually being provided as a structural unit which extends centrally or th track or side frames.

It is usual to mount upon such a structure a tool which can be utilized to cut and move earth or the like, such as a blade or bucket. H-eretofore, it has been the practice .to mount a pair of arms hingedly upon each side frame and to extend a tool transversely of the main frame and in advance thereof upon these arms, the position of the two being adjusted by moving the arms by suitable cylinder and piston mechanism extended between the side frames and the arms.

In accordance with the present invention, the tool supporting arms are hinged upon the main frame while the tool moving mechanism is supported upon the main frame in such fashion that the entire weight and load of the arms, the tool, and the load applied to the tool in working earth are transmitted, in the first instance to the main frame. Such a structure can be fashioned of fewer and generally lighter parts than those utilized heretofore to provide a structure which is more satisfactory in use and is even more ruge ged. In addition, one is able to effect a more accurate working of earth by means of a tool, for the tool is not subject to the extreme workings of the side frames as is the case when the tool is mounted upon these. Also, the forces applied to the tool in working earth are applied, in the first instance, to the main frame, thus avoiding stressing of the hinged mounting of the side frames upon the main frame.

It is in general the broad object of the present invention to provide an improved earth working tool comprising a tractor having a tool supported and to be moved by mechanism carried by the main frame of the tractor.

The invention includes other objects and fea tures of advantage, some of which, together with the foregoing, will appear hereinafter when the present preferred form of earth working tool of this invention is disclosed.

In the drawings accompanying and forming a parthereof,

Figure l is a side elevation of the present preferred form of tool.

Figure 2 is a plan View with portions of the tractor omitted or shown in outline.

Figure 3 is a section taken along the-line 3-3 in Figure 2.

Referring to the drawings, the tractor includes a main frame generally indicated by the numeral and including an engine generally indicated by the numeral l supported between forwardly extending horizontal frame members 8. Side or track frames, generally indicated by numeral 9, extend along each side of the main frame in a parallel spaced relation, the side frames being hingedly mounted on shaft II at the rear of the main frame on each side thereof. A heavy leaf spring 12 extends transversely of the main frame and supports the latter between the side frames. Continuous flexible track elements H are trained about sprockets M on each side frame to provide a ground engaging mechanism for moving the tractor. The tractor so far described is one well known in the art; insofar as reference has been made to any details thereof, this is only for convenience and illustration of the present invention.

Referring particularly to Figure 2, the underside or bottom of the main fram 6, usually the tractor transmission housing, includes a bracket structure 21 which serves to retain and position the equalizer spring 12 and to which is usually attached draw bar 22 of the tractor. In accordance with this invention, I provide an auxiliary bracket structure generally indicated by numeral 23 and which is secured to bracket 2! by arm 25, the latter having cars 25 thereon adapted to receive studs 28 which retain a portion of the bracket 2| in position. The auxiliary bracket 23 includes a transverse member 25 having plates 2? secured thereto. The plates 2'5 extend along the outside of the main frame and are suitably attached thereto. A stub shaft 28 is secured to each plate 21 and is braced thereon by suitable brace members 29. It is to be noted that the stub shafts 28 are positioned intermediate of the pivotal mounting of each side frame and the spring i2 for reasons which will presently appear.

Means are provided, in accordance with this invention, for supporting a tool structure genrally indicated at 3i upon the tractor; this means comprises a bell crank 33' and another arm 34. One hinged by a suitable bearing end of arm 33- is 36- on each stub 32 having an arm shaft. Each bell crank is so positioned upon a stub shaft that the forward end of arm 34 extends in advance of the tractor and is adapted to receive tool at, and in the drawing the tool is shown as including a bowl structur 4| having a cutting edge 62 thereon; any other suitable form of tool can be employed as desired.

To provide for raising and lowering of the tool, brackets 43 are mounted upon the rear end of the main frame which has an end at thereof extending upwardly. Angle plates at are secured to plates 2'? and provide a support for one end (Figure 1) of a box beam or auxiliary frame 35 which extends rearwardly to brackets A3 at the rear of the tractor, thus serving to tie the brackets and the plates 2; together. A cylinder 46 is hingedly mounted as at 41 upon the upper end 46 of each bracket suitable piston (not shown) being mounted within the cylinder and having a piston rod d8 extending forwardly thereof and hingedly connected as at it to the bell crank 32 at the common end of arms 33 and 3 2. When fluid is suitably supplied to or is withdrawn. from the cylinders in the well known manner, the position of the tool with respect to the tractor and the earth can be varied.

Referring particularly to Figure 1, it is to be noted that the common axis of the shafts 28 lies below a plane passed through the line of normal ground engagement of the tool, indicated by letter A in Figure l, and the common axis of the hinge mounting of each cylinder upon the upper end of each bracket d3 indicated by letter B. So long as the hinge mounting of the bell crank is below this plane, the cutting forces from the tool. 42 will be applied largely as thrust forces acting directly upon the main frame in a rearward direction. Also, a major portion of these rearward thrust forces is taken upon the stub shafts 2S and not upon the hydraulic system of the tractor. By having the forces act upon the main frame and then in a rearward direction, any tendency to lift the forward end of the tractor is minimized, if not entirely obviated; in fact, the tractor hugs the earth closely and the tool stays down to its work. This is due in part to the fact that stub shafts 28 are normally nearly as close to the earth as are shafts l I.

A further advantage and feature of the tool of the present invention is that the bulk of the weight of the auxiliary tool is carried close to the ground, little of the weight of the tool being above the center of gravity of the tractor and tool, so reducing any tendency for the tractor to be top heavy; in fact, the elevation of the axis of the stub shafts 28 is intermediate the elevation of the hinge mountings of the side frames on the main frame and the elevation of the center of gravity of the main frame; as is evident in Figure 3, the tractor is not encumbered by low hanging parts and its ground clearance is neither reduced nor impaired. This last feature is of importance in working on soft earth, mud, sand, snow or on debris covered earth.

A further feature is that the entire load of the auxiliary tool is carried on the spring supported portion of the tractor; as a result, wear and damage to tract: frames, gears and clutches is considerably reduced as compared to that which is present in tractors having tool mountings wherein part or all of the mounting is carried on the side frames. Also, because of this manner of mounting, the cutting edge on the blade has a cutting action on earth and rock much like that 4 of a crow-bar which is forced into earth and then lifted. Because of this, the tool can be used to cut virgin earth and rock of such solidarity that heretofore explosives were required to loosen it.

In connection with the bell-cranks 32, these should be so stiff that they do not bend and rub the tractor sides. Also, preferably, tool 3| should have such lateral stiffness that it does not flex between the bell-cranks 32. These are preferably rigidly pinned to the tool; in the form shown, the tool can be adjusted in position but is otherwise rigidly supported. This is accomplished by a stub-shaft 6i mounted on an end of each arm 34 and held in a clamp 62 on the tool. Stub shaft (ii is pinned to a second stub shaft 63 by a cross piece 64 while an angle hose 56 is extended from arm 34 to shaft 53 which is also held by a clamp 6'! on the tool. An eye bolt 68 secured to the tool extends through an ear B9 on arm 34 to enable the tool to be adjusted in position. The clamps 62 and iii and the eye bolt 68 support the tool in a rigid position across the arms so that a load on a corner of the tool is transmitted substantially equally to both arms 34 and thence to stub shafts 28; in effect, the tool and bell-cranks form a U frame member.

I claim:

An earth working tool adapted to be mounted upon a tractor having a pair of side frames and a main frame extending forwardly thereof, each side frame being hinged at one end on the main frame and having a continuous ground engaging flexible track, and a spring extending transversely of the main frame and supporting the main frame on and adjacent to the forward end of the side frames; said tool comprising a bracket means secured to the underside of the main frame intermediate the ends thereof, a pair of stub shafts each extending from said bracket to between the main frame and the adjacent side frame on opposite sides of said bracket and transversely of the main frame and between said spring and the hinge mounting of the side frames on the main frame, a pair of hell cranks each having a first arm extending vertically upwardly to a juncture with a second arm, said second arm projecting forwardly and downwardly to an end and in advance of the main frame, each first arm having its end hinged on a stub shaft, 2. tool mounted on the end of each second arm and extending generally transversely of the tractor, a bracket mounted on each side and at the rear of said main frame, and a cylinder pivoted on each bracket, each cylinder having a piston extended substantially horizontally to the juncture of the arms on the crank and adapted to move the bell crank to raise and lower the tool carried thereby, the axis of said stub shafts being substantially on a line with but slightly below a plane passing through the lower edge of the tool when the latter is in normal earth engaging position and the pivot mounting of the cylinders on the brackets.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,989,431 Stamm Jan. 29, 1935 2,031,463 Choate et a1 Feb. 18, 1936 2,163,662 Eufiington June 2'7, 1939 2,314,475 Bird et al. Mar. 23, 1943 2,344,584 Austin Mar. 21, 1944 2,375,801 Le Tourneau May 15, 1945 2,529,208 Andersen Nov. 7, 1950 

